As semiconductor devices become more highly integrated, a horizontal area of a unit cell on a semiconductor substrate may be gradually decreased. Although the horizontal area of the unit cell on the semiconductor substrate may be gradually decreased, it may be required to maintain a sufficiently high capacitance of a capacitor for storing charges in the semiconductor device. In order to maintain the capacitance of the capacitor, a height of a lower electrode may be increased to enlarge a contact area between the lower electrode and a dielectric layer.
However, the increased height of the lower electrode may cause the lower electrode to collapse because its aspect ratio is too high. Further, the high aspect ratio of the lower electrode may cause bending of a central portion or an upper portion of the lower electrode, so that adjacent lower electrodes may make contact with each other. Thus, a capacitor having a high capacitance and reduced susceptibility to collapse may be required.